Basic windshield wipers used on vehicles have a blade portion that contacts the windshield, a frame that supports the wiper strip, and a connection device for attaching the blade to a wiper arm. Presently, three principle styles of windshield wipers are in wide-scale use. The first style is the traditional frame windshield wiper, which implements a multi-piece frame that is directly connected to the wiper arm. The second style is the beam blade windshield wiper, which has a unitary beam that supports the wiper blade and is directly connected to the wiper arm. Wiper blades of this type are described in U.S. Patent Application No. 61/477,908, which is incorporated by reference herein in its entirety. The third style is the hybrid blade windshield wiper, which combines the multi-piece frame and the unitary beam frame. Wiper blades of this type are described in U.S. Patent Publication No. US 2010/0236008, which is incorporated herein by reference in its entirety.
One problem common among many windshield wipers is a tendency to separate from the windshield during use, thus resulting in an uneven or inconsistent clearing of the windshield. This happens when a windshield wiper encounters a vehicle's slipstream and downward force on the wiper blade is overcome by wind lift created by the wiper blade. The wind lift problem has been known in the wiper field for decades, and many attempts have been made to resolve it. For example, see U.S. Pat. Nos. 3,056,991, 3,317,945, 3,879,793, 3,942,212, 6,292,974, 6,944,905, which are incorporated herein by reference in their entirety.
To minimize the wind lift problem, covers that create desired aerodynamic characteristics are added to the top of windshield wipers. Beam blade and hybrid blade windshield wipers generally incorporate three or more deflectors or covers. Specifically, a first cover is provided between one end of the windshield wiper and the central connection device. A second cover is provided between the other end of the windshield wiper and the central connection device. And a third cover is provided over the central connection device.
Despite the significant performance, aerodynamic and aesthetic improvements created by the use of covers, these windshield wipers still have significant shortcomings. One significant problem is that the use of covers increases the material and assembly costs for each windshield wiper. Another problem is that covers are prone to unwanted separation or detachment from the windshield wiper. Separation often occurs when the vehicle is moving through inclement weather and as a result covers are frequently lost. Once a cover is lost, the performance and aesthetic qualities of the windshield wiper are significantly impaired.
Yet another problem with windshield wipers, and in particular windshield wipers with covers, is that covers can result in high profile or interrupted profile regions. Such regions can create aerodynamic turbulence or vortices that result in wind noise. This occurs as wind contacts any high profile or interrupted profile regions of the covered windshield wiper. The wind noise created from wiper blades encountering the slip stream is distracting and makes for a less comfortable overall driving experience. Reduction of such wind noise is therefore a constant concern associated with wiper blade design.